Normal activation by insulin of PI3K/Akt in Psen1-/- neurons. Primary neuronal cultures were treated with insulin for the indicated times. In panel A, Western blotting was performed for p-Akt (Ser473) followed by reprobing for total Akt. Shown are representative blots from experiments that were performed multiple times. In panel B, the time course of induction of p-Akt in primary neuronal cultures (n = 2 per genotype per time point) is shown as a ratio of p-Akt/total Akt. There were no significant differences at any time point (unpaired t-tests).